1. Field of the Invention.
This invention relates to tools for positioning electrical outlet boxes for installation on building framing members.
2. Description of the Prior Art.
Electrical boxes are commonly attached to wall studs or ceiling joists in building frames before the wall covering, such as sheet rock or paneling, is installed. For the face of the electrical box to be flush with the surface of the finished wall, the box must be offset forward of the face of the wall stud or ceiling joist. For example, if .TM. inch sheet rock were to be later installed, the front edge of the electrical box must be spaced out .TM. inches from the face of the wall studs.
To do a workman-like and esthetically pleasing job, the electrician should also position all wall outlet fixtures an equal distance from the floor. It is difficult to properly position an electrical box to get exact measurements for both these parameters. Proper positioning also slows down the installation process and reduces the productivity of the electrician.
Many attempts have been made to find a satisfactory tool for accomplishing this positioning. The following seven patents relate to tools for locating electrical boxes:
______________________________________ Inventor U.S. Pat. No. Issue Date ______________________________________ Briggs 2,956,798 10/18/60 Crawford 3,154,304 10/27/64 Utley et al 3,436,070 01/01/69 Estep 3,601,386 08/24/71 Strange 3,617,044 11/02/71 Isola et al 3,678,588 07/25/72 Hull 3,875,669 04/08/75 Duffy 4,181,295 01/01/80 ______________________________________
U.S. Pat. No. 3,678,588 to Isola et al discloses a wall outlet box locator apparatus for tracing a cut-out area in a wall panel for an outlet box. This does not appear particularly related to the present invention.
U.S. Pat. No. 3,154,304 to Crawford discloses a box tool which holds rectangular boxes for positioning against the wall stud. A clip mounts the tool on a wall stud. The tool includes a pair of clips for frictionally bearing against the inside of the box.
U.S. Pat. No. 3,436,070 to Utley et al discloses a jig for holding an electrical outlet box to a wall stud. The jig includes a pair of plates for holding the outlet box. A pole on the jig extends to contact the floor to properly position the height of the box.
U.S. Pat. No. 3,875,669 to Hull also discloses apparatus for holding an outlet box in position against a wall stud. It also uses an extending rod to set the distance from the floor. A pair of lips extending out from a plate holds the box to the apparatus.
U.S. Pat. No. 2,956,798 to Briggs discloses a hand tool for positioning an electrical box which has an adjustable rod for contacting the floor to set the height of the box. The tool includes a plate which contacts the wall stud. An adjustable stop sets the distance of the electrical box from the face of the wall stud. The box is held by a spring clip extending inside the box.
U.S. Pat. No. 3,601,386 to Estep discloses a pair of tongs with a plate on each jaw of the tongs for gripping a wall of an electrical box. Each plate has an enlarged front area for contacting the wall stud to set the distance from the front of the box to the wall stud. The distance is adjustable by setting pins in holes through the plates. The front edge of the box hits one of the pins to set its distance from the enlarged area of the plate. The tool also has an adjustable rod for determining distance from the floor.
U.S. Pat. No. 3,617,044 to Strange discloses lockable pliers having plates mounted on the jaws for gripping the wall of an electrical box. One plate has a portion adapted for contacting the face of a wall stud to set the distance from the edge of the box to the wall stud. The distance is adjustable by a slidably mounted guide bar on the plate.
U.S. Pat. No. 4,181,295 to Duffy discloses a box holder with a pair of spring clips to slide inside the wall of a rectangular box to hold it for positioning against a wall stud.
All of the prior art tools discussed above are designed to operate on traditional rectangular boxes. What is needed is a universal tool that can clamp on all types of electrical boxes, whether rectangular, square, or round. For example, lighting outlet boxes in ceilings are commonly circular in cross section. These round boxes cannot be gripped easily by any of the prior art devices. Modern plastic boxes often have tubular interior elements mounted in the box walls which are tapped to allow plates to be screwed on the face of the box. These interior appurtenances get in the way of prior art gripping devices. To solve the problems in the prior art a tool must firmly grasp an electrical box without continued hand pressure from an electrician, so that the box can be nailed to the wall stud or ceiling joist without disturbing either the grip on the box or the distance that the box is spaced from the face of the stud or joist.